The provision of subscriber service features or network service features is one of the tasks of exchanges in conventional TDM networks. This includes, for example, announcements and interactive responses which in certain situations are delivered to the A and/or B subscriber (e.g. “number unobtainable,” “the number has changed—the new number is 722-25940” or interactive responses prompting for subscriber data for the use of IN services).
These announcements and interactive responses can be provided either by peripheral devices of the exchange that are equipped with the appropriate functionality or by an external announcement and interactive response system (referred to in the following as an “IVR system” or “interactive voice response system”).
Announcements and interactive responses are necessary to the extent that a large number of operations in the exchange are controlled by operator prompts. Thus, for example, switching-oriented events such as, e.g. dialing an unobtainable number or calls with delay systems require announcements for the calling subscriber. Furthermore, services comprising interactive responses such as, e.g. interactive support for controlling independent subscriber inputs, must be implemented in the exchange. Finally, SCP-controlled IN services featuring user interactive responses should be present, these responses being controlled via the interface between SCP and exchange with SSP functionality.
A feature common to all these cases is that the control logic for the announcement and interactive response function is provided in the exchange itself or in the components (SCP) connected to the exchanges. This also applies in the case of the external announcement and interactive voice response system IVR referred to. For this reason, a control interface is required for controlling the announcements and interactive responses including variable announcement parameters, as well as for feeding back collected user inputs between exchange and external announcement and interactive voice response system IVR.
Currently, two solutions exist in the state of the art.
In the first solution approach, the announcements and interactive responses are provided in peripheral devices of an exchange. For this purpose, peripheral devices of the exchange having hardware modules for providing announcements and DTMF/voice recognition are introduced into the exchange. In order to play back an announcement or interactive response, the subscriber/trunk is switched to a port of this special peripheral device for announcements and interactive responses via a 64 kbps through-connection. From a switching-oriented viewpoint, this is a through-connection of a call routed from an A-side peripheral device via the switching network to the B-side peripheral device with announcement and interactive response functionality. The B-side announcement/interactive response port acts as a B-side trunk. The type of announcement/interactive response function to be played back is effected by exchange-internal signaling to the peripheral device with announcement and interactive response functionality or is permanently predefined.
The advantage of this integration solution lies in cost-effective provision of the announcement and interactive response function as well as in broad access to the hardware functionality of the peripheral device for announcement and interactive response functionality. A disadvantage, on the other hand, is the circumstance of a proprietary hardware, as a result of which use of the wide range of host-based voice recognition and voice synthesis algorithms is severely restricted without porting overhead. In addition, in an integration solution of this type, the announcement and interactive response system in question cannot be used as a central resource in the network.
In the second solution approach, the announcements and interactive responses are provided by external systems. For this purpose, there exist a number of solutions enabling the exchange to control the announcements and interactive responses in an external system (IVR). The proprietary application protocols (operations and parameters) are implemented on the basis of TDM signaling protocols (ISDN-PA or ISUP).
Although, in this case, in contrast to the integration solution, the announcement and interactive response system in question can be made usable as a central resource in the network, it is disadvantageous that the control interface cannot be used in the packet network.
A solution approach of this type has already been proposed in the German patent application DE 10047129.3. In that case, however, the controller is implemented exclusively for packet networks. Conventional TDM networks are not referred to in that description.